The NSW Waratahs’ backs must attack and pressure the star-studded Crusaders or run the risk of being punished in their home Super Rugby clash on Sunday, according to assistant coach Alan Gaffney.

Typically, the Crusaders – the most successful team in Super Rugby – are gathering plenty of momentum after a slow start to the season, winning four of their past five games while conceding only a controversial loss to the Bulls in Pretoria.

It’s a benchmark game for the injury-and-suspension-hit Waratahs who sit three points and one place below the Crusaders in seventh spot on the overall standings.

And there’s plenty of reason for concern with the visitors set to regain All Blacks skipper Richie McCaw from injury for his season start.

They’ve had the luxury of easing All Blacks playmaking great Dan Carter back at inside centre, while newcomer Tom Taylor impresses as a goalkicking five-eighth in a backline also featuring classy Test fullback Israel Dagg, elusive winger Zac Guildford and blockbusting centre Robbie Fruean.

Gaffney said the Crusaders’ backs posed a big threat from anywhere on the field.

“We’ve got to be pretty much direct with them. We’ve got to take them on – there’s no doubt about that,” Gaffney said.

“I’m not talking necessarily in a physical sense.

“To sit back on your heels and watch them play, you are going to get punished.

“The only way we can compete at the level they will be at is to go out there and attack them.

“I think that’s a good thing in a sense, because we have some people who like playing that way.”

Gaffney believed the Waratahs still had the backs to challenge the Crusaders despite their rash of injuries and the suspension of centre Rob Horne.

The Waratahs are also wary of the influence openside flanker McCaw could have on the game.

“He (McCaw) doesn’t work his way into a season or back from injury. He definitely comes back and has an impact straight away,” Waratahs coaching coordinator Greg Mumm said.

“That’s something we have to anticipate this weekend, if he does get on the field, whether it’s starting from the bench.

“The way they attack, Richie is going to be a big asset in terms of allowing them to secure ball right across the width of the field and support their wide attacking game.”

Having negated Western Force champion David Pocock recently, Mumm was confident NSW could counter McCaw despite the absence through injury of their most senior openside flankers Pat McCutcheon and Chris Alcock.

He thought the battle for metres between opposing No.8s Wycliff Palu of NSW and the Crusaders’ Kieran Read would go a long way towards determining which team gained momentum.

“I think that matchup is going to be very important to the outcome of the game,” Mumm said.

“Looking at both Kieran and Wycliff this year, I think they’ve both broken 15 tackles and Wycliff, even more importantly in his limited time, has had five line breaks which indicates how much of an impact he can have on the game and how much damage he can do to a defence.”

Mumm said another very interesting potential matchup was between Waratahs prop Benn Robinson and the Crusaders’ Owen Franks.